GH with NARODs for VHF-HI & UHF - Page 22 - Canadian TV, Computing and Home Theatre Forums
 

Go Back   Canadian TV, Computing and Home Theatre Forums > Canadian Internet, Phone, TV and Wireless Service Providers > Over-The-Air (OTA) Digital Television > Antenna Research & Development

Digital Home Helpful Information

Reply
 
Thread Tools Search this Thread Display Modes

Old 2009-10-04, 09:44 PM   #316
300ohm
Veteran
 
Join Date: Mar 2008
Location: Somewhere in Delaware on the flat side
Posts: 7,360
Default

Quote:
Now all I have to do is update the antenna!
Waiting for that, heh.
__________________
My builds/plans (not the latest models) are located here.
300ohm is offline  
Sponsored Links
Advertisement
 
Old 2009-10-05, 12:47 PM   #317
stampeder
OTA Forum Moderator
 
Join Date: Jan 2005
Location: North Delta, BC (96Av x 116St)
Posts: 23,893
Default

akahooper, excellent update and welcome to this site!
stampeder is offline  
Old 2009-10-22, 10:30 PM   #318
pdentrem
Rookie
 
Join Date: Jul 2009
Posts: 23
Default My DBGH

Not the best symmetry in the build but it works for what I need. I posted a picture in the photo album called "Wire straighten block and DBGH by pdentrem".

Thanks to 300ohm and the others who have posted their build ideas.

Last edited by pdentrem; 2009-10-23 at 07:12 AM. Reason: Location of picture needed clarifaction
pdentrem is offline  
Old 2009-10-22, 10:44 PM   #319
300ohm
Veteran
 
Join Date: Mar 2008
Location: Somewhere in Delaware on the flat side
Posts: 7,360
Default

Picture of the above:



Doesnt the mast get in the way of that weather vane ?
__________________
My builds/plans (not the latest models) are located here.
300ohm is offline  
Old 2009-10-23, 07:11 AM   #320
pdentrem
Rookie
 
Join Date: Jul 2009
Posts: 23
Default Weather vane

The angle of the picture is covering up the fact that the vane is mounted on a 18" standoff.
pdentrem is offline  
Old 2009-12-12, 05:38 AM   #321
JPark
Rookie
 
Join Date: Dec 2009
Posts: 2
Default

Hello all,
I've spent the last 6 hours perusing this forum and a few other helpful forums in anticipation of working on this project tomorrow (which is now today). I keep seeing references to people's plans and occasional links to plans, but those links are always broken. Could someone point me to a beginners guide to building the SBGH w/ NARODs? Mec_Eng's link cited above no longer works. 300ohm's sig says his plans are in a sticky, but all I've found are NEC files and dimensioned drawings. Both very helpful, but not the "plans" I'm looking for. I need something a bit more step-by-step. I'm not afraid to get my hands dirty and I could throw something together based on the sketches I've seen, but the last six hours have taught me that antennae are pretty sensitive to the smallest changes, so I'm trying to do it as close to "by the book" as possible.
JPark is offline  
Old 2009-12-12, 01:31 PM   #322
balm
Veteran
 
Join Date: Jan 2009
Location: Montreal
Posts: 2,399
Default

go here

http://content12.wuala.com/contents/...=1260642658940
balm is offline  
Old 2009-12-12, 03:49 PM   #323
JPark
Rookie
 
Join Date: Dec 2009
Posts: 2
Default

Thanks.
I'll take 300ohm's comments on Mec_Eng's plans in Post #201 into account and use akahooper's walkthrough for his build to guide me through the nitty gritty.
JPark is offline  
Old 2009-12-12, 03:50 PM   #324
balm
Veteran
 
Join Date: Jan 2009
Location: Montreal
Posts: 2,399
Default

maybe 300ohm is the best person to ask about this...
balm is offline  
Old 2009-12-12, 08:17 PM   #325
snowman53
 
Join Date: Aug 2009
Posts: 52
Default

Very nicely done set of drawings!

Last edited by stampeder; 2010-01-11 at 10:51 AM.
snowman53 is offline  
Old 2010-01-11, 10:11 AM   #326
bytor
Rookie
 
Join Date: Jan 2009
Location: Kalamazoo
Posts: 5
Default

Though the information is pretty good, I would be wary of the print or the parasolid file (.x_t) of the driven element. The upper and lower portions are not bent at 90 degrees and the driven element gets thin in this area which means something went wrong in either the sweep used to create this. I'd recommend using a different set of dimensions for the driven element, or if you print it out then use a square to redraw that bend which will move the 135 degree bend inward and the measured cut from that bend inward also. And that measured cut appears to be a bit longer than the 5.59" measurement found on the other set of prints I've seen

Last edited by stampeder; 2010-01-11 at 10:52 AM.
bytor is offline  
Old 2010-03-29, 05:59 PM   #327
running
Rookie
 
Join Date: Jan 2009
Posts: 28
Default

To fix the narods on GH10 rev2. I fellows the same patern than you used on SBGH ?
running is offline  
Old 2010-04-08, 05:24 PM   #328
gcd0865
 
Join Date: Feb 2009
Posts: 82
Default Alternate NAROD length/spacing?

Hi All:

Until earlier this week, I was planning a DBGH w/NARODs with the NAROD length/spacing focused on a distant RF-8, using the following measurements from this thread:

NAROD and NAROD reflector length is 30.25 inches and the NAROD to NAROD reflector distance is 11.5 inches:
CH Raw Gain dBi SWR
-- ------------ ---
07 09.04 2.81
08 11.70 2.80
09 11.50 3.32
10 11.10 2.92
11 10.70 2.48
12 10.30 2.37
13 09.99 2.66

Unfortunately, a local low-powered religious station signed onto digital RF-8 this week, ruining that plan. Since I also have a full-powered local RF-7 and distant RF-10, 11, 12 and 13, I'll focus on 10-13 now, which would call for these NAROD measurements:

NAROD and NAROD reflector length is 28 inches and the NAROD to NAROD reflector distance is 10 inches:
CH Raw Gain dBi SWR
-- ------------ ---
07 06.82 12.5 (8.71 dBi at 180 degrees)
08 07.63 3.94 (7.96 dBi at 180 degrees)
09 08.74 1.77
10 11.6 1.65
11 11.8 2.35
12 11.3 2.16
13 10.8 1.89

Just in case the religious station signs off or changes channels at some point, is there anything between the two above NAROD measurements, maybe something like 29.125 inch length and 10.75 inch separation, that would be decent on RF-13 (maybe around 10.4 raw gain) but wouldn't drop so much (and reverse its sensitivity direction) on RF-8 (maybe around 9.5 raw gain in the forward direction)? Alternatively, would a top-hat NAROD version of similar type be possible?

I'd very much appreciate any assistance anyone can provide. Thanks in advance...
gcd0865 is offline  
Old 2010-04-08, 08:23 PM   #329
300ohm
Veteran
 
Join Date: Mar 2008
Location: Somewhere in Delaware on the flat side
Posts: 7,360
Default

Quote:
maybe something like 29.125 inch length and 10.75 inch
That will give you on channel 8, 8.54 dBi Raw Gain with a SWR of 3.3. On channel 13, that would be 10.37 dBi RG with a SWR of 2.33. Both in the right direction.
__________________
My builds/plans (not the latest models) are located here.
300ohm is offline  
Old 2010-04-26, 01:01 PM   #330
wontgoin
Rookie
 
Join Date: Nov 2009
Location: Montreal H1E 3R4
Posts: 7
Default Sbgh - replace 3/8" for 1/2" narods ?

Hi,

Can we use 1/2" instead of 3/8" aluminum tubes for the NARODS and NAROD reflectors? I'm having an extremely hard time finding 3/8" tubes in places like Home Depot and Reno Depot here in Montreal, but 1/2" tubes are plentiful and the prices are great.

I suppose 3/8" copper is easier to find, but I thought I'd stick to aluminum and would like to know what modifications would be necessary for SBGH6 dimensions when using 1/2" tubing. The antenna would be tweaked for VHF-Hi channel 13 (28" length with 10" spacing). Thanks in advance.
wontgoin is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -4. The time now is 11:22 AM.

OTA Forum Sponsor


Search Digital Home

Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.